#app{
  position: relative;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

#btn{
  width: 100px;
  height: 30px;
  background-color: skyblue;
  color: #fff;
  margin-top: 10px;
  border-radius: 5px;
  cursor: pointer;
}


.go{
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%) scale(0);
  text-align: center;
}
.go.show{
  animation: show 1s linear forwards;
}
@keyframes show{
  0%{
    transform: translate(-50%,-50%) scale(0);
  }
  80%{
    transform: translate(-50%,-50%) scale(1.4);
  }
  100%{
    transform: translate(-50%,-50%) scale(1);
  }
}

.countdown{

}

.countdown.hide {
  transform: scale(0);
  animation: hide .2s linear ;
}

@keyframes hide {
  0%{
    transform: scale(1);
  }
  100%{
    transform: scale(0);
  }
}

.countdown .num_box{
  height: 35px;
  position: relative;
  overflow: hidden;
  text-align: center;
}

.countdown .num{
  position: absolute;
  left: 50%;
  top: 50%;
  color: skyblue;
  font-size: 30px;
  font-weight: 700;
  transform-origin: bottom center;
  transform: translate(-50%,-50%) rotate(120deg);
}

.countdown .num.in{
  transform: translate(-50%, -50%) rotate(0deg);
  animation: goIn .5s ease-in-out;

}

@keyframes goIn{
  0%{
    transform: translate(-50%,-50%) rotate(120deg);
  }
  30% {
    transform: translate(-50%, -50%) rotate(-20deg);
  }
  60% {
    transform: translate(-50%, -50%) rotate(10deg);
  }
  100%{
    transform: translate(-50%,-50%) rotate(0deg);
  }
}

.countdown .num.out{
  animation: goOut 0.5s linear;
}


@keyframes goOut {
  0% {
    transform: translate(-50%, -50%) rotate(0deg);
  }

  60% {
    transform: translate(-50%, -50%) rotate(20deg);
  }

  100% {
    transform: translate(-50%, -50%) rotate(-120deg);
  }
}
